Aluminium alloy conductor wire

ABSTRACT

An aluminium alloy conductor wire consists of between 98.0 and 99.5 weight percent aluminium, between 0.3 and 1.0 (preferably 0.4 to 0.6) weight percent iron, between 0.08 and 1.0 (preferably 0.2 to 0.4) weight percent copper, a maximum of 0.15 (preferably 0.05 to 0.08) weight percent silicon, and trace quantities of conventional impurities. The conductor wire is especially suitable for use as a conductor of a telecommunication cable or as a component element of an overhead electric conductor.

United States Patent 1 1' Raw et al.

1 ALUMINIUM ALLOY CONDUCTOR WIRE both of England [73] Assignee: British Insulated Callenders I Cables, Limited [22] Filed: Nov. 30, 1973 21 Appl. No.: 420,592

[30] Foreign Application Priority Data Aug. 9, 1973 Great Britain 37870/73 [52] US. Cl. 174/23 R, 174/126 R, 174/128 [51] Int. Cl. H0lb 1/02 [58] Field of Search..... 29 /193, 180 S; 174/126 CP, 174/126 R, 23, 27, 128, 130

[56] References Cited UNITED STATES PATENTS 3,261,908 7/1966 Roche et al 174/128 3,264,404 8/1966 Trebby et al. 174/130 3,378,631 4/1968 Edwards 174/130 3,445,586 5/1969 Edwards et a1. 174/130 3,496,285 2/1970 Slethei 174/130 3,619,480 11/1971 Bauer 174/130 1 Oct. 15, 1974 3,647,939 3/1972 Schoerner 174/130 3,676,578 7/1972 Cahill 174/128 3,795,760 3/1974 Raw ct al 174/128 OTHER PUBLICATIONS Standards For Aluminum Mill Products, The Aluminum Assoc, Eighth Ed. 1965, pp. 10, 21, 74.

Metals Handbook, 8th Ed., 1961, Vol. American Soc. of Metals pp. 943-945.

Primary Examiner-A. T. Grimley Attorney, Agent, or Firm-Buell, Blenko & Ziesenheim [5 7] ABSTRACT An aluminium alloy conductor wire consists of between 98.0 and 99.5 weight percent aluminium, between 0.3 and 1.0 (preferably 0.4 to 0.6) weight percent iron, between 0.08 and 1.0 (preferably 0.2 to 0.4) weight percent copper, a maximum of 0.15 (preferably 0.05 to 0.08) weight percent silicon, and trace quantities of conventional impurities. The conductor wire is especially suitable for use as a conductor of a telecommunication cable or as a component element of an overhead electric conductor.

11 Claims, 2 Drawing Figures ALUMINIUM ALLOY CONDUCTOR WIRE This invention relates to elongate members of aludrawn, and after annealing each hard-drawn wire at several different temperatures.

. TABLE I minium alloy su1table for use in formmg a conductor, or an element of a multr-element conductor, of an elec- 5 "on Copper 5mm tr1c cable or an electric msulated wire, all such elongate Content Content Content members heremafter, for convemence, bemg 1ncluded 5 1n the generic term conductor wire. Alloy A 0.51 trace 0.041 It is an ob ect of the present lnventlon to provide an 2: 1;? improved conductor wire of an aluminium alloy con- 10 3; D 13 2; taming iron as the principal alloying constituent which Alloy E (179 9058 has a hlgher tensile strength and higher percentage ulti- TABLE 11 Temperature Electrical 0.1% Proof Tensile Elongation Alloy of Annealing Conductivity Stress Strength 7o on Treatment C lACS MN/m MN/m' 250 mm.

A As drawn 61.4 177 221 1.6 B do. 60.5 245 344 1.4 C do. 59.1 244 354 1.1 D do. 58.0 277 402 1.8 E do. 57.0 275 376 1.5 A 200 62.3 143 164 0.4 13 do. 60.5 165 199 0.4 C do. 60.2 168 201 0.5 D do. 60.3 174 209 0.6 E do. 59.5 158 218 0.8 A 250 62.3 111 120 1.8 B do. 61.2 130 144 8.8 C do. 60.5 123 151 10.0 D do. 60.3 115 150 9.2 E do. 60.1 118 156 12.0 A 275 62.9 79 107 26.0 B do. 61.7 87 128 18.5 C do. 61.0 78 136 17.5 D do. 60.4 80 141 16.0 E do. 59.9 82 144 16.0 A 300 62.9 50 103 31.5 B do. 61.8 62 122 22.5 C do. 605 62 129 19.0 D do. 598 65 142 16.0 E do. 59.4 68 145 16.5 A 350 63.3 104 27.0 B do. 61.6 52 119 22.0 C do. 60.1 55 131 19.0 D do. 59.6 60 142 16.0 E do. 58.5 59 149 16.0

mate elongation than wires of known aluminium alloys which contain similar quantities of iron.

According to the invention our improved conductor wire is composed of an aluminium alloy consisting of betwen 98.0 and 99.5 weight percent aluminium, between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; at maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.

The copper content of the aluminium alloy preferably lies in the range 0.2 to 0.4 weight percent.

Preferably the iron content lies in the range 0.40 to 0.60 weight percent and the silicon content lies in the range 0.05 to 0.08 weight percent.

A conductor wire in accordance with the present in-v vention has significantly improved tensile strength as compared with that of conductor wires of the same diameter of known aluminium alloys containing similar quantities of iron but only a trace quantity of copper and the improved tensile properties of our improved conductor wire are illustrated by the following results achieved with a conductor wire of a known aluminium alloy (Alloy A) having a diameter of 0.5 mm and with conductor wire in accordance with the present invention (Alloys B, C, D and E) of the same diameter, as

The greater improvement in tensile strength of conductor wires of the present invention as compared with that of conductor wires of the known aluminium alloy occurs withthe copper content of the aluminium alloy lying in an upper part of the specified range of 0.08 to 1.0 weight percent.

' Although in some instances conductor wires of the present invention show a slight loss in electrical conductivity as compared with a conductor wire of a known aluminium alloy containing a similar quantity of iron and only a trace quantity of copper, i.e., approximately 0.001 weight percent, the improvement in tensile strength for a given elongation renders our im proved conductor wires especially suitable for use in telephone cables and in other cables where a high tcnsile strength is desirable and a high electrical conductivity is not of primary importance. Moreover, conductor wires in accordance with the present invention, especially those of an aluminium alloy having a copper content in an upper region of the quoted range, display relatively high tensile strength even in the fully annealed condition. In addition, since in some instances conductor wires of the present invention in an unannealed condition, though having a slightly lower electrical conductivity than a conductor wire of a known aluminium alloy containing a similar quantity of iron and only a trace quantity of copper, have a tensile strength that is at least 50 percent greater than that of the unannealed conductor wire of the known alloy, unannealed conductor wires of the present invention are especially suitable for use in overhead electric conductors where tensile strength is a primary consideration.

The conductor wire of the present invention may be prepared by any of the known processes for preparing aluminium alloy wire but we prefer to prepare our improved conductor wire by continuously casting a bar of our aluminium alloy and immediately rolling the bar down to rod form, subsequently drawing the rod to the required wire size and finally annealing the wire.

The invention also includes an electric insulated wire comprising a conductor wire as hereinbefore defined provided with at least one covering layer of insulating material, for instance an extruded layerof plastics insulating material, and the invention further includes an electric cable comprising at least one insulated conductor comprising a plurality of conductor wires as hereinbefore defined and, enclosing the insulated conductor or conductors, an outer protective sheath.

The invention further includes a telecommunication cable comprising a multiplicity of insulated conductors, each conductor comprising a conductor wire as hereinbefore defined. The conductors may be insulated with solid or cellular plastics material and the interstices between the insulated conductors and between them and a surrounding water-proof sheath from end to end of the cable length may be filled with a waterimpermeable medium of a grease-like nature.

The invention still further includes an overhead electric conductor comprising at least one'conductor wire as hereinbefore defined.

The invention will be further illustrated by a description, by way of example, of a-telecommunication cable and of an overhead electric conductor each incorporating conductor wires of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional end view of the telecommunication cable, and

FIG. 2 is a cross-sectional'end view of the overhead electric conductor.

The telecommunication cableshown in FIG. 1 comprises twenty-five pairs ofv insulated conductors each consisting of an aluminium alloy wire 1 of diameter 0.50 mm and an insulating covering 2 of extruded cellular polyethylene of radial thickness 0.014 mm. The aluminium alloy of each wire 1 consists of 99.0 weight percent aluminium 0.59 weight percent iron; 0.32 weight percent copper; 0.07 weight percent silicon and trace quantities of conventional impurities. Wire 1 has an electrical conductivity of 60.7 percent lACS, a 0.1 percent proof stress of 90 MN/m a tensile strength of 138 MN/m and elongation on 250 mm of 16.9 percent. The assembly of insulated conductors is surrounded by a longitudinally applied, transversely folded polyester tape 4, a longitudinally applied, transversely folded aluminium tape 5 and an extruded polyethylene sheath 6. The interstices between the insulated conductors and between the insulated conductors and the polyester tape 4 are filled with a water-impermeable medium 3 comprising highly refined petroleum jelly.

The overhead electric conductor shown in FIG. 2 is of overall diameter 42.5 mm and comprises a stranded core 11 of seven steel wires each of diameter 4.72 mm which is surrounded by three stranded layers 12, 13 and 14 of round aluminium alloy wires 15 of diameter 4.72 mm, the direction of lay of the wires of each layer being opposite to that of the wires in the or each adjacent layer. The aluminium alloy of each wire 15 consists of 99.14 weight percent aluminium; 0.5-weight percent iron; 0.3 weight percent copper; 0.06 weight percent silicon and trace quantities of conventional impurities.

What we claim as our invention is;

1. A conductor wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.

2. A conductor wire as claimed in claim 1, wherein the iron content of the aluminium alloy lies in the range 0.40 to 0.60 weight percent and the silicon content lies in the range 0.05 to 0.08 weight percent.

3. A conductor wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium between 0.3 and 1.0 weight percent iron, between 0.2 and 0.4 weight percent copper; a maximum of 0.15 weight percent silicon and trace quantities of conventional impurities.

4. A conductor wire as claimed in claim 3, wherein 0.40 to 0.60 weight percent and the silicon content lies in the range 0.05 to 0.08 weight percent.

5. A conductor wire as claimed in claim 1, which has at least one covering layer of insulating material.

6. An electric cable comprising at least one conductor comprising a plurality of conductor wires, each conductor wire being composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0'weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.

7. A telecommunication cable comprising a multiplicity of insulated conductors, each conductor comprising a wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.

8. A telecommunication cable comprising a multiplicity of insulated conductors, each conductor comprising a wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0. 15 weight percent silicon; and trace quantities of conventional impurities, a water-proof sheath enclosing the insulated conductors and, filling the interstices between these insulated conductors and between them and the cable sheath from end to end of the cable length, a water-impermeable medium of greaselike nature.

9'. A telecommunication cable as claimed in claim 8, wherein the insulation of each conductor is a plastics material of cellular form.

10. An overhead electric conductor comprising at least one stranded layer of wires, wherein at least some of the wires are composed of an aluminium alloy conwires each composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities. 

1. A CONDUCTOR WIRE COMPOSED OF AN ALUMINUM ALLOY CONSISTING OF BETWEEN 98.0 AND 99.5 WEIGHT PERCENT ALUMINUM; BETWEEN 0.3 AND 1.0 WEIGHT PERCENT IRON; BETWEEN 0.08 AND 1.0 WEIGHT PERCENT COPPER; A MAXIMUM OF 0.15 WEIGHT PERCENT SILICON; AND TRACE QUANTITIES OF CONVENTIONAL IMPURITIES.
 2. A conductor wire as claimed in claim 1, wherein the iron content of the aluminium alloy lies in the range 0.40 to 0.60 weight percent and the silicon content lies in the range 0.05 to 0.08 weight percent.
 3. A conductor wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium between 0.3 and 1.0 weight percent iron, between 0.2 and 0.4 weight percent copper; a maximum of 0.15 weight percent silicon and trace quantities of conventional impurities.
 4. A conductor wire as claimed in claim 3, wherein the iron content of the aluminium alloy lies in the range 0.40 to 0.60 weight percent and the silicon content lies in the range 0.05 to 0.08 weight percent.
 5. A conductor wire as claimed in claim 1, which has at least one covering layer of insulating material.
 6. An electric cable comprising at least one conductor comprising a plurality of conductor wires, each conductor wire being composed of an aluminIum alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.
 7. A telecommunication cable comprising a multiplicity of insulated conductors, each conductor comprising a wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.
 8. A telecommunication cable comprising a multiplicity of insulated conductors, each conductor comprising a wire composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities, a water-proof sheath enclosing the insulated conductors and, filling the interstices between these insulated conductors and between them and the cable sheath from end to end of the cable length, a water-impermeable medium of greaselike nature.
 9. A telecommunication cable as claimed in claim 8, wherein the insulation of each conductor is a plastics material of cellular form.
 10. An overhead electric conductor comprising at least one stranded layer of wires, wherein at least some of the wires are composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities.
 11. An overhead electric conductor comprising a core of metallic elements of high tensile strength and, surrounding the core, at least one stranded layer of wires each composed of an aluminium alloy consisting of between 98.0 and 99.5 weight percent aluminium; between 0.3 and 1.0 weight percent iron; between 0.08 and 1.0 weight percent copper; a maximum of 0.15 weight percent silicon; and trace quantities of conventional impurities. 